The present invention relates generally to the implementation of a mechanism to convert Time Domain Multiplexed (TDM) circuits into scheduled Internet Protocol (IP) packet flows. These scheduled IP packets traverse a network as an itinerary of appointments. The method herein calculates the required number of appointments per itinerary, as well as possible packet sizes, schedule efficiency, and packetization delay.
Service Providers have expressed the desire to carry TDM circuits—especially private line services—on their IP backbone networks. The goal is to reduce the operational expense of managing separate TDM and IP networks. Circuit emulation over Asynchronous Transport Mode (ATM) networks is another possibility, but introduces another network layer and associated operational expense.
The conversion of TDM circuits to conventional IP packets is not new, and efforts are underway to standardize one or more approaches. One such standards arena is the Internet Engineering Task Force (LEIF) Pseudo Wire Emulation Edge-to-Edge (PWE3) Working Group. The Working Group recognizes that there may be limitations in their approach, given that IP does not offer the same level of quality of service as a TDM circuit does.
A TDM circuit, once established, offers a bandwidth that is completely free of contention from other circuits. If an application or service has a dedicated TDM circuit, then it has guaranteed bandwidth at all times.
A conventional IP network cannot make such claims for any of the flows in its network, as long as there is more than one flow that contends for bandwidth somewhere along the path. Various prioritization and traffic engineering schemes have been proposed and implemented to combat this problem, but the result remains that jitter-free bandwidth cannot be guaranteed.
Real-Time Scheduled Packet Networks provide deterministic, scheduled flow paths for IP packets with minimal queuing delay and no jitter or packet loss. This technology is ideal for real-time IP traffic and for emulating TDM circuits.